One thing to try is removing your Java versions and reverting to Java 1.5_10 as sometimes that can make a difference. Not sure in your case. Step 1 here Fixes for Limewire (click on blue link). Since LW was working fine before, this might not be the answer.

Something else to try is go to LW's menu bar, Tools > Options > Advanced > Performance and disable Ultrapeer and DHT and TLS. Then press apply. Then connect manually. If it connects, then can re-enable those performance options.